Alert archive / Georgia / Mesoscale Discussions in 2012

Mesoscale Discussion 230

March 3, 20129 counties in Florida; 30 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Mar 3, 2012, 9:12 AM CST for 9 counties in Florida; 30 counties in Georgia. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
Mar 3, 2012, 9:12 AM CST (15:12 UTC)
Expired
Mar 3, 2012, 10:45 AM CST
In force
93 min
Issued by
the Storm Prediction Center
All 39 counties

Bay County, FL, Calhoun County, FL, Gadsden County, FL, Hamilton County, FL, Jefferson County, FL, Leon County, FL, Liberty County, FL, Madison County, FL, Wakulla County, FL, Appling County, GA, Atkinson County, GA, Bacon County, GA, Berrien County, GA, Brantley County, GA, Brooks County, GA, Bryan County, GA, Charlton County, GA, Clinch County, GA, Coffee County, GA, Colquitt County, GA, Cook County, GA, Decatur County, GA, Echols County, GA, Effingham County, GA, Evans County, GA, Grady County, GA, Irwin County, GA, Jeff Davis County, GA, Lanier County, GA, Liberty County, GA, Long County, GA, Lowndes County, GA, McIntosh County, GA, Pierce County, GA, Tattnall County, GA, Thomas County, GA, Tift County, GA, Ware County, GA, Wayne County, GA

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 3.2 hours before the alert went out and 126 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Tallahassee Rgnl, FL at 12:00Z on 2012-03-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 499 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tallahassee Rgnl, FL at 12:00Z on 2012-03-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 257 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
499 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
472 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
257 m²/s²
0-3 km storm-relative helicity
283 m²/s²
Significant tornado parameter
0.9
Supercell composite
4.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

956 
ACUS11 KWNS 031513
SWOMCD
SPC MCD 031512
SCZ000-GAZ000-FLZ000-031645-

MESOSCALE DISCUSSION 0230
NWS STORM PREDICTION CENTER NORMAN OK
0912 AM CST SAT MAR 03 2012

AREAS AFFECTED...PARTS OF NRN FL...SE GA...AND SRN SOUTH CAROLINA

CONCERNING...TORNADO WATCH 68...

VALID 031512Z - 031645Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 68 CONTINUES.

THE REMAINDER OF WFO JACKSONVILLE COUNTIES NEAR AND NORTH OF THE
GEORGIA BORDER MAY NEED TO BE ADDED TO WW 68.  WFO CHARLESTON SC
GEORGIA COUNTIES ARE BEING MONITORED FOR A POSSIBLE INCREASING
SEVERE THREAT WITHIN THE NEXT FEW HOURS.

STORMS ARE SLOWLY INTENSIFYING WITHIN A PRE-FRONTAL CONVECTIVE BAND
EXTENDING INLAND ACROSS THE FLORIDA PANHANDLE...THROUGH SOUTHERN
GEORGIA INTO THE LOWER SAVANNAH RIVER VALLEY AREA.  PERHAPS MOST
PROMINENT IS AN EVOLVING CLUSTER TO THE WEST AND NORTH OF
TALLAHASSEE...WHICH MAY BE ASSOCIATED WITH AN AREA OF ENHANCED
FORCING FOR UPWARD VERTICAL MOTION COINCIDING WITH A WEAK FRONTAL
WAVE.  THROUGH 17-19Z...THIS ACTIVITY APPEARS LIKELY TO ADVANCE EAST
NORTHEASTWARD ACROSS SOUTHERN GEORGIA AND ADJACENT NORTHERN
FLORIDA...TOWARD GEORGIA COASTAL AREAS TO THE SOUTH OF SAVANNAH.
EMBEDDED WITHIN A 40+ KT WEST SOUTHWESTERLY DEEP LAYER MEAN
FLOW...ALONG AND NORTH OF A 40+ KT 850 MB JET AXIS...IN THE PRESENCE
OF MIXED LAYER/MOST UNSTABLE CAPE ON THE ORDER OF 500 TO 1000
J/KG...POTENTIAL FOR DAMAGING WIND GUSTS MAY INCREASE THIS MORNING.
ALTHOUGH LOW-LEVEL HODOGRAPHS ARE NOT EXHIBITING PRONOUNCED
CLOCKWISE CURVATURE...SHEAR REMAINS STRONG ENOUGH TO SUPPORT A
CONTINUING RISK FOR ISOLATED TORNADOES...PARTICULARLY IN DISCRETE
CELLS FORMING JUST AHEAD OF THE DEVELOPING LARGER-SCALE CONVECTIVE
SYSTEM.

..KERR.. 03/03/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...CHS...JAX...FFC...TAE...

LAT...LON   30298600 30848477 31718317 32168211 32508146 32268100
            31518134 30678194 30268342 29908500 30298600

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 2, 10:56 PM CSTTornado WatchSPCEscambia6 hr
Mar 3, 4:47 AM CSTMesoscale DiscussionSPCBay, Calhoun, Escambia, Franklin, Gadsden, Gulf and 10 more58 min
Mar 3, 6:35 AM CSTTornado WatchSPCBay, Calhoun, Franklin, Gadsden, Gulf, Hamilton and 9 more6 hr
Mar 3, 11:45 AM CSTMesoscale DiscussionSPCAlachua, Baker, Bradford, Clay, Columbia, Duval and 15 more60 min
Mar 3, 12:04 PM CSTTornado WatchSPCAlachua, Baker, Bradford, Calhoun, Clay, Columbia and 17 more5 hr
Mar 3, 3:30 PM CSTMesoscale DiscussionSPCBaker, Columbia, Hamilton, Lafayette, Nassau, Suwannee and 2 more90 min
Mar 2, 7:15 PM CSTMesoscale DiscussionSPCCatoosa, Dade, Fannin, Gilmer, Murray, Rabun and 4 more90 min
Mar 2, 7:18 PM CSTMesoscale DiscussionSPCDade57 min
Mar 2, 8:36 PM CSTMesoscale DiscussionSPCBaker, Calhoun, Colquitt, Cook, Decatur, Dougherty and 6 more54 min
Mar 2, 9:54 PM CSTTornado WatchSPCBanks, Barrow, Bartow, Butts, Carroll, Catoosa and 61 more6 hr
Mar 2, 10:07 PM CSTMesoscale DiscussionSPCCarroll, Clayton, Cobb, Coweta, DeKalb, Douglas and 13 more113 min
Mar 2, 11:40 PM CSTMesoscale DiscussionSPCBanks, Barrow, Bartow, Carroll, Cherokee, Clarke and 30 more95 min
Mar 3, 2:58 AM CSTMesoscale DiscussionSPCBurke, Columbia, Glascock, Jefferson, Jenkins, Lincoln and 6 more92 min
Mar 3, 3:39 AM CSTSevere Thunderstorm WatchSPCBurke, Columbia, Lincoln, McDuffie, Richmond4 hr

Nearby

Mesoscale Discussions in Georgia, 2012Mesoscale Discussions in Florida, 2012Every mesoscale discussion in 2012

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive.